DIVE LOG AUSTRALASIA FEB 2025 ISSUE 410

Diving with sharks

text and photos by Mike scotland

S everal decades ago, when I was less cautious and diving was far more adventurous, I asked the skipper of the boat I had chartered for a group of social divers if I could circum-navigate a very remote and isolated rocky reef south of Little Seal Rocks by myself. He trusted me and consented. He pointed out where he planned to anchor the boat three hundred metres at the other end of the rocky reef. Tiger shark at the Aqua Trek shark feed in Beqa Lagoon in Fiji. This 4 and 1/2female shark named Emma is eating Tuna Heads offered by the famous shark feeder, Tukai.

After taking a compass bearing and planning the dive, keeping the rocky reef to my left, off I went! I had my ‘buddy in a box’, my underwater camera and I was brimming with anticipation about the photo opportunities that might come from this venture. Along the way, I discovered that the many gutters and channels were home to more than seventy juvenile Grey Nurse sharks. This was a nursery for sub adult sharks! Mind you, I did cling close to the sea floor and often looked over my shoulder for that sneaky ‘Great White shark that my imagination kept telling me was lurking directly behind me. As I swam into the next gutter, a dozen or so sharks would drift away and down into deeper water. There is no way that I would do this kind of dive these days. The maritime management has fully protected the Great White Sharks over the last decades and their numbers are escalating dramatically. Back in the eighties, the GWS population was much lower due to the extensive fishing practices of the day. Therefore, the oceans were a lot safer. Shark segregation is a very common phenomenon that it observed frequently, especially amongst Port Jackson Sharks and Grey Nurse sharks. More often than not, you will see a dozen sharks which are all female or all male. As you dive more and more, you might begin to notice annual variations in the make-up of shark numbers. Over the late

winter months, Port Jackson sharks will migrate many hundreds of kilometres from Bass Straight to Jervis Bay and the Sydney region for the annual mating aggregation during July, August and into September. During this time, it is possible to see more than a hundred ‘Porties’ on a single dive at special locations. These can be packed tightly into crevices and overhangs often stacked up on top of each other. They always appear to be exhausted and in a state of deep rest, readying themselves for the mating rituals ahead. Grey Nurse also display sexual segregation and undertake long distance migrations. Grey Nurse males tend to aggregate at the Solitary Islands in early winter. They also migrate south over eh summer to places like Jervis Bay and Montague Island. Grey Nurse also make use of shark creches where juvenile sharks remain together in small groups. One summer, we ‘night snorkeled’ at the Docks in Jervis Bay from Ocean trek with a small colony of juvenile Grey Nurses. There are places where massive females also tend to assemble such as the Pinnacle at Forster. Like many sharks and rays, the females are far larger, more bulky and powerful than males. When you see a mature female Grey

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DIVE LOG Australasia #410 February‘25

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